48 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 8 



ritory in the northwest, its distribution following, in a general way, 

 that of the tick as given below. Spotted fever has not been well known 

 among physicians in the wide range of territory indicated by the scat- 

 tering cases reported and it is probable that many cases have passed 

 unrecognized. It is best known in Montana and Idaho; and' in Mon- 

 tana interest in the disease centers in the Bitter Root valley where 

 most of the cases have occurred. 



In Idaho the number of cases reported ranges around 375. to 400 

 per year with an average mortality of approximately 5 per cent ; ^ while 

 in the Bitter Root valley, Montana, the cases have ranged from 28 

 downward with an average of about 12 during recent years, but with 

 a mortality of around 85 per cent. The fact that spotted fever is so 

 fatal in Montana accounts for this state's being the center of interest 

 in this disease. 



Influence on Property Values and Business 



There can be no doubt that the presence of spotted fever has in- 

 fluenced property values and the volume of business in the immediate 

 region affected and also that exaggerated reports which have become 

 current in the United States have injured the reputation of the state as 

 a whole. Outside of the Bitter Root valley, and the region close around, 

 spotted fever occurs in Montana; so far as is known, onl}^ in a restricted 

 area in Carbon county, just north of Wyoming. In Idaho and Wyom- 

 ing, and in Carbon county, Montana, spotted fever is not much 

 feared on account of the low mortality and property values are not 

 much affected. 



Evidence Against the Tick 



From the fact that ticks and tick bites were found on the bodies of 

 fever patients, some residents in the Bitter Root valley had formed 

 the opinion that ticks were the infective agents before scientists an- 

 nounced this fact. 



The tick hypothesis first attracted general attention when Doctors 

 Wilson and Chowning published the results of their study made in 

 1902 and 1903. The work of D.octor H. T. Ricketts, under the aus- 

 pices of the Montana State Board of Health, established the fact of 

 tick transmission, although somewhat earlier than his work, Doctors 

 McCalla and Brereton in Boise, Idaho, had actually infected a man and 

 a woman with the mild form of spotted fever by allowing a tick to at- 

 tach to them which had been removed from a fever patient. Doctor 

 Ricketts' work was experimental and methodically carried out. He 

 repeatedly infected guinea pigs and other animals by means of ticks 



iMaxey, Medical Sentinel, Portland, December, 1908. 



